Closure combination and method

ABSTRACT

A closure bushing molded of synthetic plastic material has a cylindrical wall surrounded by a circumferential retaining shoulder and terminates at one end in a laterally extending octagonally shaped flange. The bushing wall is molded with an oversize pitch diameter internal straight pipe thread. Insertion of the bushing within a suitably sized container wall opening reduces the bushing wall interior to a standard pipe thread pitch diameter for reception of a threaded closure fitting.

United States Patent 1191 11] 3,828,418 Laurizio Aug. 13, 1974 [54] CLOSURE COMBINATION AND METHOD 3,468,0l3 9/1969 Scianonte et al. 29/45l nventor: Jeremiah J- Laurizi N w FOREIGN PATENTS OR APPLICATIONS Provldence, 1,334,334 7/1963 France 220/39 R Assignee: & Great Bl'ltaln R Co., Inc., New York, NY. [22] Filed Nov 6 1972 Primary ExaminerRichard J. Herbst [21] Appl. No.: 304,239 [57] ABSTRACT A closure bushing molded of synthetic plastic material g 29/451 g; has a cylindrical wall surrounded by a circumferential 58] g i 456 retaining shoulder and terminates at one end in a lat- /453 220739 1 erally extending octagonally shaped flange. The bush- 1 ing wall is molded with an oversize pitch diameter intemal straight pipe thread. Insertion of the bushing [56] References C'ted within a suitably sized container wall opening reduces UNITED STATES PATENTS the bushing wall interior to a standard pipe thread 2,210,353 8/1940 Barnes 29/456 pitch diameter for reception of a threaded closure fit- 2,936,0l4 5/1960 Kraus et al 29/451 tin 3,219,230 11/1965 Housz et al. 220/39 R g 3,424,481 1/1969 Fulghum 220/39 R 5 Claims, 7 Drawing Figures CLOSURE COMBINATION AND METHOD BACKGROUND OF THE INVENTION Numerous attempts have been made to duplicate the conventional steel closure bushing with plastic substitutes in order to reduce packaging costs while retaining the required strength and closure efficiency. Of those attempts which have attained commercial acceptance,

reliance has been placed on the employment of a metal securing ring for crimping an internally threaded plastic bushing onto an upstanding neck surrounding the container wall opening. Such arrangements, however, have not been wholly successful in achieving the sought after cost reduction. Other complete plastic closure arrangements have been proposed but the they, too, suffer from cost deficiencies and in addition lack the necessary structural requirements in terms of torque resistance and sealing efficiency.

The invention improves over the above mentioned prior art closure constructions in providing an all plastic closure bushing which is easily pressed into a simply formed container wall opening. The low cost invention bushing meets essential strength requirements and also achieves a high degree of sealing efficiency. This is accomplished by molding the bushing wall internal thread pitch diameter to an oversize dimension and reducing that pitch diameter to a decreased dimension upon insertion of the bushing .within the container wall opening. The threaded opening thus formed is sized to just the correct pitch diameter dimension to properly receive a standard externally threaded closure fitting.

It is accordingly a principal object of the invention to provide a new plastic closure bushing container wall combination.

Another object is to provide a new method of forming a threaded closurereceiving opening in a container wall.

A further object is to provide an internally threaded container wall opening by inserting a molded plastic closure bushing within the container wall opening and resizing the bushing by the insertion operation for reception of a threaded closure member.

Other and more detailed objects will in part be obvious and in part pointed out as the description of the invention taken in conjunction with the accompanying drawing proceeds.

In that drawing:

FIG. 1 is an exploded sectional view of the closure bushing container wall combination of the invention;

FIG. 2 is a view similar to FIG. 1 showing the bushing partially inserted within the container wall opening;

FIG. 3 is a view similar to FIG. 2 showing the bushing fully inserted within the container wall opening; FIG. 4 is a perspective view of the invention fitted with a closure fitting dispensing tap;

FIG. 5 is a part sectional part elevational view of a modified form of the invention fitted with a closure P g;

FIG. 6 is a partial sectional view of another modification; and

FIG. 7 is a partial sectional view of a still further modification.

In FIG. 1 a container wall 1 is shown as having a circular opening 2 surrounded by a downwardly and radially inwardly extending conical neck 3 terminating at its lowermost extent in a free edge 4. The neck 3 extends downwardly from a depressed embossment having a horizontal annular wall 5 joined to the neck 3 and surrounded by a substantially vertical octagonal sidewall 6 extending downwardly from the container wall 1.

Also shown in FIG. 1 is a closure bushing 10 molded of synthetic plastic material comprising a cylindrical wall 11 terminating at its upper end in a circumferential octagonally shaped flange 12. The lowermost end of the bushing 10 is closed off with an integrally formed sealing diaphragm 13. A circular score line line 14 surrounds the undersurface of the diaphragm 13 forming a reduced cross sectional thickness to facilitate separation of the diaphragm from the bushing. A circumferentially enlarged shoulder 15 is formed on the exterior surface of the bushing wall 11 provided with a lower upwardly and radially outwardly inclined conical surface 16, an outwardly facing vertical surface 17 and an upper annular horizontal surface 18.

The interior of the bushing wall 11 is initially molded with an internal straight pipe thread 19 having a predetermined oversize pitch diameter indicated at A, the thread pitch diameter A being greater than required for proper threaded reception of a standard closure fitting. The molded bushing 10 is substantially inserted within the container wall opening 2 and, as seen in FIG. 2, as the lower inclined surface 16 of the shoulder 15 moves past the opening neck 3, the bushing wall 11 is severely radially constricted. At this intermediate insertion position, the neck free edge 4 surrounds the nozzle shoulder vertical surface 17 and the bushing thread 19, lying in the horizontal plane of the free edge 4, is reduced to an undersize pitch diameter B substantially less than the initially molded oversize pitch diameter A. The inherent flexibility of the bushing cylindrical body 11 permits the necessary constriction of the bushing internal diameter causing the sealing diaphragm to flex upwardly imparting a concave configuration to the lower surface of the diaphragm 13. The final increment of downward movement required to insert the bushing 10 within the container wall opening 2, causes the bushing shoulder vertical surface 17 to move past the opening neck 3 at the same time the flange 12 contacts the container embossment surface 5. As clearly seen in FIG. 3, the bushing wall 1 l expands radially outwardly with the neck free edge 4 seating itself on the upper surface 18 of the bushing shoulder 15 forming a rigid leakproof joint. In the above described fully seated position of the bushing within the container wall opening, the cylindrical wall 1] partially returns to its originally molded dimension resulting in the formation of an internal thread pitch diameter C in the plane of the neck edge 4, which is just slightly greater than the constricted pitch diameter B and slightly smaller than the originally molded pitch diameter A.

With this arrangement the bushing wall is constantly held under tension to aid the sealing efficiency of the bushing container wall joint. Most importantly, however, the resultant pitch diameter at the zone of sealing engagement with the container opening neck, indicated at C, is just the optimum dimension required for threaded reception of a standard closure fitting. In FIG. 4 a dispensing tap 20 is shown threadedly engaged within the bushing 10 which engagement has caused the diaphragm 13 to separate from the wall 11 along the weakened score line 14. The relatively minor upward flexing of the diaphragm 13 in the fully seated position of the bushing adds a degree of rigidity to the score line 14 so as to aid the puncturing action of the tap 20. It should be noted, however, that the diaphragm could just as well be punctured or cut out with an implement in those instances where the packaging requirements call for the use of a threaded closure plug.

A modification of the above described invention is illustrated in FIG. wherein the opening formation in the container wall is just the reverse of that employed in the principle embodiment. In this form the container wall opening is surrounded by an upwardly drawn neck 33 extending from a raised embossment having a flat top wall 35 surrounded by an octagonal side wall 36. A molded plastic bushing 40, identical to bushing 10, except for the omission of the sealing diaphragm, is provided with an internally threaded cylindrical wall 41 surrounded by an octagonal base 42 and an external retaining shoulder 45. The internally threaded wall 41 undergoes the same pitch diameter changes as above described during insertion of the bushing from the undersurface of the container wall 30. A standard thread size closure plug 50 is sealingly engaged with the bushing to complete the closure assembly and is seen to have an externally threaded side wall 51 terminating at its upper end in a circumferentially enlarged head 52 and an internal wrench engaging recess indicated at 53.

In FIG. 6 a further modification of the invention is illustrated wherein a bushing 60 is inserted within a container wall opening formation similar to that shown in FIG. 1. The bushing 60 is also formed with an internally threaded cylindrical wall 61 surrounded by a retaining shoulder 65 and terminating at its upper end in an octagonal flange 62. A downwardly protruding sealing annulus 63 is formed on the undersurface of the flange 62 and provides additional assurance against formation of a leakage path between the bushing and the container wall.

FIG. 7 is directed to another modification similar to that shown in FIG. 6, the bushing being formed with an internally threaded cylindrical wall 71 surrounded by a retaining shoulder and terminating at its upper end in an octangonal flange 72. In this form the undersurface of the flange is provided with an annular recess 73 within which a resilient sealing gasket 74 is retained.

Having described my invention, what I claim is as follows:

1. The method of forming an internally threaded opening in a container comprising the steps of molding from a synthetic plastic material a hollow cylindrical bushing having an oversize pitch diameter internal straight pipe thread, inserting said bushing within a container wall opening and reducing said oversize internal straight pipe thread to a decreased pitch diameter upon completion of said insertion for reception of an externally threaded closure member.

2. The method as in claim 1 and momentarily further reducing said bushing oversize pipe thread to a pitch diameter less than said decreased pitch diameter during said insertion.

3. The method as in claim 2 and returning said further reduced bushing pitch diameter to said decreased pitch diameter.

4. The method as in claim 1 and mechanically interlocking said bushing within said opening.

5. The method as in claim 1 and forming relative rotation preventing means between said bushing and said container wall. 

1. The method of forming an internally threaded opening in a container comprising the steps of molding from a synthetic plastic material a hollow cylindrical bushing having an oversize pitch diameter internal straight pipe thread, inserting said bushing within a container wall opening and reducing said oversize internal straight pipe thread to a decreased pitch diameter upon completion of said insertion for reception of an externally threaded closure member.
 2. The method as in claim 1 and momentarily further reducing said bushing oversize pipe thread to a pitch diameter less than said decreased pitch diameter during said insertion.
 3. The method as in claim 2 and returning said further reduced bushing pitch diameter to said decreased pitch diameter.
 4. The method as in claim 1 and mechanically interlocking said bushing within said opening.
 5. The method as in claim 1 and forming relative rotation preventing means between said bushing and said container wall. 